What Is the Best Speaker Wire Size for Car Audio?

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When setting up your car audio system, one of the most important decisions you’ll have to make is what size speaker wire to use.

There are a few things to consider when deciding, and it’s not always as simple as just choosing the biggest wire you can find.

The best speaker wire size for most factory car audio is the 18AWG. The correct wires size for aftermarket stereo and upgraded speakers is the 16AWG. The best speaker wire size for car speakers with over 150W RMS per channel is 14AWG and 12AWG for around 200W RMS.

Tip: If the car audio includes the amplifier and the subwoofer, the speaker size will depend on a few factors, including the power of your stereo, the size of your speakers, and the length of your speaker wire run. 

For the quality speaker wires, I recommend KnuKonceptz (link to Amazon), from which you can choose the most suitable gauge for your system.

In this article, I’ll look at some of the factors involved in choosing speaker wire size for your car audio system and will help you figure out which option is best for you.

What Speaker Wire Size Should Be Used for Car Audio?

Generally, for most car audio systems, the speaker wire size will be between 16 and 18 gauge based on the American Wire Gauge (AWG).

The lower the AWG number, the thicker the wire. For example, the 12AWG speaker wire is much thicker than the 16AWG speaker wire.

The most important factor when choosing speaker wire size for car audio is its resistance, and the thicker the wire, the lower the resistance.

Speaker wire size for car audio systems should have a resistance of less than 5% to avoid negatively affecting sound quality.

Another factor to consider is the length of the speaker wire run. The longer the speaker wire run, the higher the resistance will be, so the best effect you will have when the cables are as short as possible.

For example, a 16AWG speaker wire running 20 feet will have a higher resistance than a 16AWG speaker wire running 10 feet.

Finally, the power of your stereo and speakers will also be a factor in choosing speaker wire size for car audio. The higher the power, the thicker the speaker wire should be.

What Is the Standard-Speaker Wire Size for Car Audio Systems?

There is no standard speaker wire size for car audio systems, but in most cases, the good enough speaker wire size will be 18 gauge.

There are too many variables to consider, and the most important one for the speaker wires is the speakers’ RMS power and the impedance.

The best speaker wire size for your system will depend on the power of your stereo, the size of your speakers, the length of your speaker wire run, and the resistance of the speaker wire.

In addition to that, there are two speaker wires types:

#1. CCA (Copper Clad Aluminum): speaker wires with a copper core and an aluminium outer layer. CCA speaker wire is less expensive than OFC speaker wire but has a higher resistance at the same gauge.

#2. OFC (Oxygen Free Copper): speaker wires with a pure copper core. OFC speaker wire is more expensive than CCA speaker wire, but it is a better option for audio systems.

For more information, check out a detailed guide about CCA wires.

What Speaker Wire Size Should Be Used for Car Subwoofers?

Choosing speaker wire size for subs has identical principles as for the speakers, except for the subwoofers, you will use thicker wires (with lower AWG) because they need to handle more power.

The speaker wire size for subwoofers will usually be between 12 and 14 gauge, depending on the amp’s power and the subs’ size.

If you have a powerful amp and large subwoofers, you may even need to go up to 10 or 8 gauge to make sure of the flawless power distribution from the amplifier.

The last thing you want, especially for the advanced car audio systems, is to compromise the bass strength because of using too thin speaker wires.

Keep in mind that the speaker wire size for subs will also be affected by the length of the speaker wire run. The longer the speaker wire run, the higher the resistance will be, so make sure to use as short a speaker wire as possible.

Although there are many different designs, I never had longer speaker wires between the amp and subwoofer than 3-4 feet, simply because I always place the amp as close to the sub as possible.

To reduce the wiring distance even more, you may bolt the amplifier to the sub’s enclosure, but for most systems, a difference in the wires’ length of 1 or 2 feet will not affect the sound or power loss.

How to Calculate Speaker Wire Size Needed?

Speaker wire size calculation can be tricky because of many parameters to consider, but there are speaker wire size calculators that will do all the work for you.

There are many speaker wire size calculators online, but my favourite is the one from SoundCertified. Just enter the values for your system, which will give you the necessary speaker wire size.

Conclusion

Speaker wire sizes for car audio systems are standardized, and most speaker wires will be between 16 and 18 gauge.

The speaker wire size for subwoofers will usually be between 12 and 14 AWG because of the larger power handling capability.